Jackson Pollock, 1912-1956, American painter, was one of the leading exponents of Abstract Expressionism, particularly the form known as Action Painting. After considerable stylistic experimentation, he developed about 1947 the radical "drip painting" technique that became his hallmark.

Pollock's family left Cody, Wyo., 11 months after his birth, and he grew up in California and Arizona. In 1930 Pollock followed a brother to New York City, where he enrolled at the Art Students League under his brother's teacher, the regionalist painter Thomas Hart Benton. In the fall of 1935 he came to be employed on the WPA Federal Art Project as an easel painter. This provided economic security during the years of the Great Depression and the opportunity to develop his art through early 1943. In 1937 he began psychiatric treatment for alcoholism, and he briefly suffered a nervous breakdown in 1938. From 1939 through 1941 he was in treatment with two successive Jungian psychoanalysts, who used Pollock's own drawings in the therapy sessions. In 1943, after the liquidation of the Federal Art Project, he was given a contract by Peggy Guggenheim at her Art of This Century Gallery in New York City, and his first one-man show was held there in November. Thereafter he had one-man shows of new work nearly every year. In 1945 he married the painter Lee Krasner and moved to East Hampton, Long Island, N.Y., where he lived until his death in an automobile accident.

Pollock's artistic development can be divided into six periods. From his years with Benton to 1938, his work was strongly influenced by the compositional methods and regionalist subject matter of his teacher and consisted mostly of small landscapes and figurative scenes. After his breakdown and hospitalization in 1938 until the time of his first one-man show in 1943, his work was semiabstract and shows the assimilation of motifs from the modern Spanish artists Pablo Picasso and Joan Miró as well as the Mexican muralist José Clemente Orozco. Jungian symbolism and Surrealist theory also influenced the works of this period. Paintings such as "Bird," "Male and Female," and "Guardians of the Secret" reflect these influences in their powerful biomorphic forms and seething imagery.

Late in 1943 or early in 1944, Pollock painted his first wall-size work, called "Mural." This painting is his breakthrough into a totally personal style in which Benton's compositional methods and energetic linear invention are fused with Surrealist free-association of motifs or unconscious imagery. His evolution from this point through the 1940s shows a struggle to find a process by which he could translate unconscious imagery into painting. The figurative character of such works as "The Totem, Lesson I," and "The Blue Unconscious" contrasts with the heavily painted allover design of "Shimmering Substance" and "Eyes in the Heat" and indicate the range of imagery and technique he employed during this period. From the early 1940s on, Pollock also created numerous works on paper, ranging from drawings to mixed-media paintings that parallel the development of his work on canvas.

In 1947 Pollock first used the process of pouring or dripping enamel or aluminum paint onto a flat canvas in stages, often taking weeks of alternating periods of painting and contemplating to finish a canvas. This process permitted him to record the force and scope of his gestures in trajectories of enamel or aluminum paint that "veiled the image" found in his earlier work. The results were huge areas covered with complex and dynamic linear patterns that fuse image and form and engulf the vision of the spectator in their scale and intricacy. A whole series of paintings--beginning with "Full Fathom Five" and proceeding through "Summertime" and "Number Ten, 1949" to the mural-size canvases of 1950 such as "One," "Autumn Rhythm," "Lavender Mist," and the black and white "Number Thirty-two, 1950"--display the infinite variety of effect and expression that this method--poured painting--permitted him. In 1951 and 1952 he painted almost exclusively in black and white, creating works in which his earlier imagery partially reappears. Among the important paintings of this phase are "Number Twenty-Three, 1951," "Echo," and Number Seven, 1952." In 1952 he returned to colour and mural-scale in "Convergence" and "Blue Poles." In 1953 he created his last series of major works. "Portrait and a Dream," "Easter and the Totem," "Ocean Greyness," and "The Deep," among other works, recapitulate many aspects of his former styles and images. Though his production waned and his health deteriorated after 1953, Pollock did produce important paintings such as "White Light" and "Scent" in his last years.

Pollock believed that art derived from the unconscious and judged his work and that of others on its inherent authenticity of personal expression. During his lifetime he received widespread publicity and some serious recognition for the radical "drip" or pouring technique he used to create his major works. In the early 1950s, when he emerged into public notice, his name became synonymous with extreme artistic caprice, since the novelty of his "drip" technique overshadowed his obsession with the personal expression which that technique may have permitted. By the time of his death in 1956, his work and example were exerting an enormous influence on his contemporaries both in the United States and western Europe. He was one of the few American painters to be recognized during his lifetime and afterward as the peer of 20th-century European masters of modern art.